SpeedyCEUS

 

Nursing Care of Patients taking Antidepressants

Presented By:

 

Jennifer Meyering, RN, BSN, MS, CCRN

 

 

Approvals:This activity for  1 contact hour has been approved by the Alabama State Nurses Association, which is accredited as an approver of continuing education in nursing by the American Nurses Credentialing Center's Commission on Accreditation.

Provider approved by the California Board of Registered Nursing, Provider Number CPE 14462 for  1 contact hours.

 

 

Objectives:

• List three general symptoms of depression
• State the pharmacodynamics and pharmacotherapeutics of medications used to treat depression
• Explain the nursing care of patients taking MAO inhibitors, selective serotonin reuptake inhibitors, and tricyclic antidepressants

 

General overview of depression

Major depressive disorder is a syndrome of a persistent sad mood that lasts at least 2 weeks.  Along with the feeling of sadness, the patient must also have at four of the following:

• Feelings of guilt, hopelessness, or helplessness
• Poor concentration
• Sleep disturbances
• Lethargy
• Appetite loss
• Inability to feel pleasure
• Loss of uplift in mood in response to something positive
• Thoughts of death

 

Major depression can significantly change a person’s social, family, and occupational functioning. Suicide- the most serious complication of major depression- can occur if feelings of worthlessness, guilt, and hopelessness overwhelm the person so much that they consider life is no longer worth living.  Almost 15% of patients with untreated depression commit suicide- and statistics show that most of them sought help from a doctor within 1 month of their death.

At some time in their lives, about 22% of women and 16% of men in the United States experience major depressive disorder.  The incidence of major depression increases with age.  Although depression can occur at any age, onset usually occurs in early adulthood, with recurrences throughout the patients’ lifetime.

Recurrences may follow a prolonged symptom-free period or may occur sporadically.  For some people, recurrences come and go in clusters.  For others, recurrences become frequent with age. More than 50% of patients who have one episode of major depression go on to have at least two more.  An untreated episode can last anywhere from one month to a year- or even longer.

 

Genetic, biochemical, physical, psychological, and social factors have been implicated as causes of major depression.  The relationship between psychological stress, stressful life evens, and depression onset is unclear.  However, the patient history often reveals a specific personal loss or severe stress.  According to one theory, the stressor interacts with the person’s predisposition to provoke major depression.

Depression is two to three times more common in people with first-degree relatives with the disease.  This suggests that there may be genetic vulnerability to developing major depression.  Although some researchers believe a single depression gene exists, mounting evidence suggests several genes may actually be involved in depression.

The neural network of the brain’s prefrontal cortex and basal ganglia may be the primary defect sites in major depressive disorder.  The serotonin, neuroendocrine and hypothalamic-pituitary-adrenal regulation systems may also be involved in development of depression.  All antidepressants currently available exert their therapeutic effects on these neurotransmitters or receptors.

 

Health care professional must distinguish major depression for depression caused by a specific event or a recognizable organic condition.  Secondary depression can result from a wide range of physical disorders, including:

• anemias
• cancer (especially of the pancreas)
• cardiovascular disorders, such as COPD
• collagen vascular diseases, such as lupus
• endocrine disorders, such as diabetes and Cushing’s disease
• genitourinary problems, such as incontinence
• GI disorders, such as irritable bowel syndrome
• metabolic disturbances, such as hypoxia and hypercalcmia
• musculoskeletal disorders, such as degenerative arthritis
• neurologic diseases, such as Parkinson’s disease and Alzheimer’s disease
• viral and bacterial infections, such as influenza and pneumonia.

 

Drugs prescribed for certain medical and psychiatric conditions can cause depression; examples include:

• antihypertensives
• antimicrobials
• antiparkinsonian drugs
• chemotherapeutic agents
• cimetidine
• narcotic and non-narcotic analgesics
• numerous cardiovascular medications
• oral antidiabetics
• psychotropics
• steroids.

Alcohol use may also contribute to depression.

 

During an initial assessment, a patient with major depression may seem unhappy or apathetic.  He may also report subjective complaints such as:

• appetite changes
• changes in bowel habits
• difficulty thinking or concentrating
• disinterest in sex
• easy distractibility
• feeling down in the dumps
• indecisiveness
• low self-esteem
• poor coping
• sleep disturbances.

 

The patient may complain that the symptoms are worse in the morning and improve during the day.  You may also note objective symptoms, such as agitation or psychomotor slowing.  A patient with severe depression may have delusions of persecution or guilt, which may have an immobilizing effect.

The patient’s psychosocial history may reveal life problems or losses that help explain or contribute to depression.  Or, the medical history may implicate a physical disorder or use of a prescription drug or other substance that can cause depression.

 

 

Pharmacodynamics and pharmacotherapeutics of antidepressants

Medication is the most effective means of achieving remission and preventing relapse in patients with major depression.  Generally, antidepressants work by modifying the activity of relevant neurotransmitter pathways.  Antidepressant agents fall into several major categories:

• atypical antidepressants
• monoamine oxidase inhibitors (MAOIs)
• selective serotonin reuptake inhibitors (SSRIs)
• serotonin/norepinephrive reuptake inhibitors (SNRIs)
• tricyclic antidepressants (TCAs).

 

No ideal antidepressant exists for all patients.  The prescriber must consider the patient’s metabolism, possible adverse effects, agents that have been effective with family members, and potential for toxicity.

Whichever drug is prescribed, the patient’s response should be reevaluated after the first 2 months of therapy and dosage changes made as needed.  After remission has been achieved, drug therapy should continue for at least 6 to 9 months.

 

Atypical antidepressants include:

• buproprion (Wellbutrin)
• maprotiline
• mirtazapine (Remeron)
• nefazodone (Serzone)
• trazodone (Desyrel)

 

These drugs’ mechanism of action aren’t well understood.  Buproprion was once through to inhibit the reuptake dopamine; however its action is more likely on non-adrenergic receptors.  Maprotiline and mirtazapine are thought to work by increasing the amount of norepinephrine, serotonin, or both in the central nervous system by blocking their reuptake by presynaptic neurons.  Nefazodone is though to inhibit neuronal uptake of serotonin and norepinephrine.  It’s also a serotonin antagonist, which makes it useful in treating anxiety.  Trazadone’s effect is unknown, although it’s thought to exert antidepressant effects by inhibiting the reuptake of serotonin and norepinephrine in the presynaptic neurons.

All atypical antidepressants are used to treat depression.  Trazodone may also be effective in treating aggressive behavior and panic disorder.  Nefazodone is sometimes used to treat anxiety.

 

MAOIs include:

• phenelzine (Nardil)
• trancyclopromine (Parnate)

 

MAOIs appear to work by inhibiting monoamine oxidase, an enzyme that’s widely distributed that normally metabolizes many neurotransmitters, including norepinephrine and serotonin.  This action makes more epinephrine, dopamine, and serotonin available to the receptors, which helps relieve the symptoms of depression.

Indications for MAOIs are similar to those for other antidepressants.  MAOIs are particularly effective in panic disorder with agoraphobia, eating disorders, posttraumatic stress syndrome, and pain disorder.  MAOIs are also thought to be effective in atypical depression.  Atypical depression produces signs opposite of those of typical depression. 

MAOIs may be used to treat typical depression resistant to other therapies or when other therapies are contraindicated.  Other uses include the treatment of:

• phobic anxieties
• neurodermatitis
• hypochondriasis
• refractory narcolepsy.

 

 

SSRIs include:

• citalopram (Celexa)
• escitalopram (Lexapro)
• fluoxetine (Prozac)
• fluvosamine (Luvox)
• paroxetine (Paxil)
• sertraline (Zoloft).

 

SSRIs inhibit serotonin reuptake and may inhibit the reuptake of other neurotransmitters as well.

SSRIs are used to treat major depressive episodes.  They may also be useful in treating panic disorders, eating disorders, personality disorders, impulse control disorders, and anxiety disorders.  Paroxetine, for example, is indicated for use in social anxiety disorder.  Fluoxetine is approved for the treatment of bulimia.  Both fluoxetine and sertaline are approved for treating premenstrual disorder.  Fluovaxamine, fluoxetine, sertaline, and paroxetine are used to treat obsessive-compulsive disorder.  Paroxetine and sertraline and used to treat posttraumatic stress disorder.  Escitalopram is also indicated for use in treating general anxiety disorder.

 

SNRIs include:

• venlafaxine (Effexor)

SNRIs inhibit norepinephrine uptake.  They are used to treat major depression, but are generally a second-line agent.

 

TCAs include:

• amitriptyline
• amoxapine
• clomipramine (Anafranil)
• desipramine (Norpramin)
• doxepin (Sinequan)
• imipramine (Tofranil)
• nortriptyline (Pamelor)
• trimipramine (Surmontil)

 

The exact action of TCAs is unknown, but it is believed that they increase the amount of norepinephrine, serotonin, or both in the central nervous system by preventing their reuptake into the storage granules in the presynaptic nerves.  Preventing reuptake results in increased levels of these neurotransmitters, in the synapses, relieving depression.  TCAs also block acetylcholine and histamine receptors.

TCAs are used to treat episodes of major depression.  They’re especially effective in treating depression of insidious onset accompanied by weight loss, anorexia, or insomnia.  Physical signs and symptoms may respond after 1 to 2 weeks of therapy; psychological symptoms after 2 to 4 weeks. 

TCAs may be helpful when used with a mood stabilizer in treating acute episodes of depression in patients with type 1 bipolar disorder.  TCAs are also used to prevent migraine headaches and treat:

• panic disorder with agoraphobia
• urinary incontinence
• ADHD
• obsessive-compulsive disorder
• diabetic neuropathy
• enuresis.

 

Nursing care of patients taking antidepressants

Patients taking antidepressants require careful observation, both before and during therapy.  Patients who are actively experiencing a major depression may save their medication for a later suicide attempt.  All of the classes of antidepressants have boxed warnings regarding suicidality in children and adolescents.  During antidepressant therapy, the patient should have ongoing monitoring of vital signs, drug levels, and other laboratory work, such as complete blood counts, liver function tests, and blood chemistry tests, as appropriate. 

Before starting any antidepressant, you should obtain baseline orthostatic vital signs.  Some medications, such as TCAs and MAOIs, may affect vital signs requiring ongoing monitoring during therapy.

Responsibilities of the nurse caring for a patient who is on an antidepressant include making sure that the patient is receiving a therapeutic dose of the medication, assessing the patient for compliance with his medication regime, and assessing for effectiveness of the medication. Tools that can be used to monitor the effectiveness of the medication include:

• objective observations
• patient’s subjective reports
• rating scales administered over the course of treatment
• vital signs.

Individualizing dosages is important for achieving the optimal efficacy for the patient.  For some medications, this is based on patient feedback; for other medications, such as TCAs, there are standardized blood levels that help determine the correct dosage.  When drawing a blood sample to measure the level of the drug, make sure to draw the sample as close to 12 hours after the patient takes the medication as possible.

All of the antidepressants have side effects and adverse reactions.  Helping the patient minimize the side effects helps increase their compliance with the medication regime.  Many patients who stop taking antidepressants without their practitioner’s approval do so because they feel the side effects of the medication are worse than the depression.  Discussing side effects and adverse reactions with the patient and providing patient teaching often helps increase patient compliance.

 

Nursing care of patients taking MAOIs

MAOIs are effective antidepressants, but their use is limited by their potential to cause severe adverse reactions and potentially fatal interactions, such as hypertensive crisis.  Because MAOIs irreversibly inhibit monoamine oxidase, it may take up to 2 weeks after stopping the drug for normal metabolism to be restored.

An MAOI is generally given in divided doses to help minimize side effects.  Common side effects include headache, drowsiness, dry mouth, constipation, blurred vision, and orthostatic hypotension. Adverse effects of MAOIs often increase as the dose increases.  Adverse effects of MOAIs include:

• anorexia
• joint pain
• mucous membrane hemorrhage.
• peripheral edema
• rash
• urine retention
• weakness.

The most serious adverse reactions to MAOIs involve changes in blood pressure and hypertensive crisis.  These reactions are more common in elderly patients and patients with a history of hypertension, cardiovascular or cerebrovascular disease.  If you are caring for one of these patients and they are taking an MAOI, be alert to changes in their blood pressure.

 

Certain foods can interact with MAOIs and produce a severe reaction, call hypertensive crisis.  This most often occurs when the patient ingests tyramine-containing food, such as red wine, beer, or aged cheese. Symptoms of a hypertensive crisis include severe pounding headache, tachycardia, flushing, stiff neck, chest pain, and nausea and vomiting.  The patient requires immediate emergency attention to decrease his blood pressure and prevent any complications, such as stroke or heart attack.  Caffeine may also interact with MAOIs, but the reactions aren’t as serious as with tyramine-containing substances.

 

MAOI also interact with many drugs.  MAOI drug interactions include:

• MAOIs administered with meperidine may lead to excitation, hyper- or hypotension, hyperthermia, and coma.
• MAOIs and doxapram may cause hypertension and arrhythmias.
• MAOIs with amphetamines, methylphenidate, levodopa, or sympathomimetics may cause a hypertensive crisis by increasing the catecholamine release.
• MAOIs with fluoxetine, TCAs, citalopram, trazodone, sertraline, paroxetine, and fluvoxamine may cause an increased body temperature and excitation and seizures.

 

When providing nursing care to a patient taking an MAOI, keep these additional points in mind:

• Closely monitor the patient’s blood pressure and be alert for signs of hypertensive crisis.
• Continue to monitor the patient for adverse reactions for up to 10 days after stopping the medication because of its long-lasting effects.
• Teach the patient about tyramine-containing foods and stress the importance of avoiding them.
• Help the patient slowly change position to minimize orthostatic hypotension.
• Watch patient older than 60 because they are more prone to adverse reactions.

 

Nursing care of patients taking SSRIs

SSRIs are one of the newer antidepressant drugs.  They have become the first choice of treatment for most patients.  SSRIs lack most of the disturbing adverse effects that are associated with MAOIs and TCAs.  However, a patient taking SSRIs still require careful monitoring to avoid dangerous adverse reactions and drug interactions. 

Some of the more common adverse reactions that occur with SSRIs include anxiety, insomnia, somnolence, and palpitations.  The patient may also experience sexual dysfunction (either anorgasm or delayed ejaculation) or skin rashes.  Fluoxetine has been associated with decrease plasma glucose.  Patients taking citalopram and paroxetine should be carefully monitored for orthostatic hypotension.  SSRIs have also been linked with an increase in suicidial ideation and aggression.  These patients need careful monitoring, especially in the early stages of treatment, when suicidial ideation increases are most common.

One of the most severe adverse reactions of SSRIs may occur when the patient stops taking the medication.  Abrupt discontinuation of SSRIs may result in a condition call SSRI discontinuation syndrome.  This syndrome is characterized by dizziness, vertigo, ataxia, nausea, vomiting, muscle pains, fatigue, tremor, and headaches.  The patient may also experience psychological symptoms, such as anxiety, crying spells, irritability, sadness, memory problems, and vivid dreams.  SSRI discontinuation syndrome is estimated to occur in up to 33% of all patients who take an SSRI.  It is more common in patients who take an SSRI with a short half-life, such as paroxetine.  Fluoxetine has a long half-life, and is the least likely SSRI to cause this problem.  SSRI discontinuation syndrome usually resolves within 2 to 3 weeks, and can usually be prevented by slowly tapering the drug over several weeks.

 

There are many drug interactions that you need to be aware of when caring for a patient taking an SSRI.  Many of the drug interactions with SSRIs are associated with their ability to competitively inhibit one of the liver enzymes that helps metabolize numerous drugs, including TCAs, antipsychotics, carbamazepine, metoprolol, and flecainide.  Using SSRIs with MAOIs can cause a serious, potentially fatal reaction, caused serotonin syndrome.  The patient may have symptoms such as sweating, fever, diarrhea, increased motor activity, muscle spasms, and altered mental state.  In severe cases, the patient may develop cardiovascular shock.

Individual SSRIs also have their own particular drug interactions:

• Citalopram and paroxetine with warfarin may lead to increased bleeding
• Citalopram may be excreted more rapidly with carbamazepine
• Fluoxetine increases the half-life of diazepam
• Fluvoxamine with diltiazem may cause bradycardia
• Paroxetine metabolism may be decreased by cimetidine, phenobarbital, and phenytoin
• Paroxetine shouldn’t be used with tryptophan because headache, nausea, sweating and dizziness may occur.

Always check all medications that the patient is taking and notify the practitioner of any possible interactions.

 

When providing nursing care for patients taking an SSRI, there are few additional points to consider:

• Provide comfort measures for the patient so they can tolerate the adverse effects. 
• Administer the medication in the morning to help prevent insomnia.
• Encourage the patient to change position slowly to help prevent orthostatic hypotension.
• Teach the patient about the risks of abruptly stopping their medication.  Encourage them to take the medication as ordered.

 

Nursing care of patients taking TCAs

Although TCAs are very effective in treating depression, they have a high potential for cardiovascular toxicity.  Patients taking a TCA should have frequent cardiovascular monitoring, including electrocardiograms.

Many of the adverse reactions of TCAs are related to their effects on the central and peripheral nervous system.  These adverse effects include drowsiness, sedation, hallucinations, disorientation, difficulty concentration, ataxia, and muscle weakness.

TCAs also cause GI anticholinergic adverse effects including:

• anorexia
• constipation
• diarrhea
• dry mouth
• increased salivation
• nausea and vomiting.

TCAs can also cause adverse effects on other body systems, such as the cardiovascular and genitourinary system.  Adverse effects that may occur include orthostatic hypotension, hypertension, arrhythmias, palpitations, urinary retention, and loss of libido.  Other adverse effects that have been reported by patients taking TCAs include hair loss, changes in weight, chills, and nasal congestion.  Rarely, TCAs can cause granulocytopenia, transient eosinophilia, and decreased white blood cell count.

When caring for a patient taking a TCA, it’s important to tell the patient not to stop the medication without discussing it with his practitioner.  Abruptly stopping a TCA can lead to a withdrawal syndrome that is characterized by nausea, headache, vertigo, and nightmares.

 

TCAs interact with many common medications, including cimetidine, fluoxetine, and ranitidine.  Specific drug interactions include:

• TCAs taken with amphetamines and sympathomimetics may cause hypertension.
• TCA metabolism is increased when taken with barbiturates.
• TCA metabolism is decreased when taken with cimetidine.
• TCAs taken with anticholinergics increase adverse effects such as dry mouth, constipation, and urine retention.
• TCAs decrease the antihypertensive effects of clonidine.

If at all possible, the combination of TCAs and MAOIs should be avoided.  This combination leads to an increased risk of hyperpyretic crisis.  Symptoms of hyperpyretic crisis include severe convulsions, hypertension, and death.  Allow at least two weeks between stopping one agent and starting the next to help minimize the risk of this interaction.

 

When providing nursing care for a patient taking a TCA, remember these additional points:

• If the patient has diabetes, or is on an oral hypoglycemic agent carefully monitor their glucose level; it may be altered by the TCA.
• Give the patient ice chips, hard candy, or sugarless gum to help relieve their dry mouth.
• Carefully monitor the patient’s blood pressure before, during, and after therapy.
• Tell the patient to avoid exposure to sunlight or artificial ultraviolet light because of the risk of photosensitivity reactions.
• TCAs can be lethal when taken in large doses- carefully monitor a suicidal patient and make sure they aren’t hoarding the pills for a suicide attempt.

 

References

 

American Psychiatric Association. (2000). Practice guidelines for the treatment of patients with major depressive disorder (2nd ed.). Washington, D.C.: Author

 

Aschenbrenner, D., and Venable, S. (2009). Drug Therapy in Nursing (3^rd ed.). Philadelphia: Lippincott Williams & Wilkins.

Boyd, M.A. (2008). Psychiatric Nursing: Contemporary Practice (4^th ed.). Philadelphia: Lippincott Williams & Wilkins.

Gutierrez, K. (2008). Pharmacotherapeutics: Clinical reasoning in primary care (2^nd ed.). Philadelphia: W.B. Saunders, Co.

Mann, J.J., Emslie, G., Baldessarini, R.J., et al. (2006). American College of Neuropsychopharmacology Task Force report on SSRIs and suicidal behavior in youth, Neuropsychopharmacology, 31(3) 473-492.

 

Psychopharmacology (2^nd ed.). (2006). Arlington, Va.: American Psychiatric Publishing, Inc.